Travel Nightmare

London's Heathrow airport has been the worst affected, with more than 300 flights cancelled Friday as the chaos continues into a third day.

Forecasters at Britain's Meteorological Office estimate that patches of fog could linger until Monday, Christmas Day, especially in England and Wales.

British Airways has scrapped all of Friday's domestic services in and out of Heathrow, after hundreds of flights were axed Thursday.

Regrettable weather

Long-haul services are expected to continue but some passengers are likely to face delays of several hours.

"The weather across much of the UK is regrettably showing little sign of improvement for Friday and therefore we have no option but to make some more cancellations," said Geoff Want, BA's director of ground operations.

He apologized for the disruption due to "unprecedented" fog.

"We understand that Christmas is an extremely important time of year for our customers and their families and we are working around the clock to give every assistance possible," he said.

Blankets and hot drinks

The inside of the airport resembles a refugee camp as hundreds of people camp out while awaiting their flights.

Passengers waiting overnight in freezing conditions at Heathrow were offered blankets and hot drinks by BA staff.

Some 70,000 people have been affected, according to The Daily Telegraph.

It is not only Heathrow which has been hit -- London Gatwick and a string of smaller airports are also facing serious delays.

Finding alternatives

BA is offering coach services for 3,000 people to travel to the cities of Manchester, Newcastle, Glasgow, Edinburgh and Aberdeen where flights are going ahead as usual, with similar services to Paris and Brussels.

Domestic train operators are providing extra seats while one potential alternative for those trying to get to mainland Europe, the Eurostar train, reported a 15 percent surge in bookings since Wednesday.

The delays and cancellations came as an estimated three million Britons were due to travel abroad between Friday and January 2, according to the Association of British Travel Agents.

An expensive disruption

Maurice Fitzpatrick, business analyst at financial and business adviser Grant Thornton, said that the disruption is likely to cost the British economy at least eight million pounds (12 million euros, $16 million) through lost productivity.

Customers are being advised to check with their airline before traveling.

The fog enveloping parts of Britain has also disrupted ferry services to Ireland and forced the postponement of Tuesday's League Cup quarter-final football match between Liverpool and Arsenal.